function Map() {   
 	var struct = function(key, value) {   
  		this.key = key;   
  		this.value = value;   
 	}   
 	var put = function(key, value){   
  		for (var i = 0; i < this.arr.length; i++) {   
   			if ( this.arr[i].key === key ) {   
    			this.arr[i].value = value;   
    			return;   
   			}   
  		}   
   		this.arr[this.arr.length] = new struct(key, value);   
	}   
    
 	var get = function(key) {   
  		for (var i = 0; i < this.arr.length; i++) {   
   			if ( this.arr[i].key === key ) {   
     			return this.arr[i].value;   
   			}   
  		}   
  		return null;   
 	}   
    
 	var remove = function(key) {   
  		var v;   
  		for (var i = 0; i < this.arr.length; i++) {   
   			v = this.arr.pop();   
   			if ( v.key === key ) {   
    			continue;   
   			}   
   			this.arr.unshift(v);   
  		}   
 	}   
    
 	var size = function() {   
  		return this.arr.length;   
 	}   
    
 	var isEmpty = function() {   
  		return this.arr.length <= 0;   
 	}
	
	var element = function(i){
		return this.arr[i];  
	}
	
	var clear = function(){
		this.arr = new Array();
	}
 	this.arr = new Array();   
 	this.get = get;   
 	this.put = put;   
 	this.remove = remove;   
 	this.size = size;   
 	this.isEmpty = isEmpty;   
	this.clear= clear;
	this.element= element;
}   